As BPA Concerns Rise, Can Companies Seek Alternatives

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Canned foods have been getting the cold shoulder from a growing
number of grocery shoppers lately -- not because of their
nutritional content or their taste, but because the linings of
most metal food cans contain the chemical BPA.

The ubiquitous chemical, also known as bisphenol A, is a
hormone-disruptor that may contribute to developmental and
reproductive problems.

Some companies already use BPA-free metal cans. But most continue
to line their cans with epoxy coatings that have a BPA base --
and for good reason, said chemist John Rost, chairman of the
North American Metal Packaging Alliance, Inc., an industry trade
organization in Washington, D.C.

"They work better than any other material on all performance
characteristics," Rost said, including corrosion resistance,
physical flexibility and resistance to high heat during the
sterilization process.

As a result, he said, today's metal cans are highly effective at
preventing foodborne diseases, which kill 5,000 Americans,
hospitalize 325,000 and sicken 76 million each year, according to
estimates by the Centers for Disease Control and Prevention.

Food safety is high on the nation's priority list these days,
with the Senate passing a bill on Tuesday that would overall the
nation's food safety program. The bill, which needs to be meshed
with a House version, would grant the U.S. Food and Drug
Administration broader power to police food companies.

Canned foods, Rost pointed out, have not caused a single case of
foodborne illness since epoxy coatings became the gold standard
for canned foods more than three decades ago.

"There's a real food safety issue here, we have a technology
that's been virtually flawless for over 36 years, and yet people
are asking us to make changes," Rost said. "We want to make sure
that any changes don't happen prematurely and affect food safety
issues. We try to share with everyone the science on epoxy
coatings so that they can see it's a real balancing act."

Food-canning technology has come a long way since the invention
of the tin can in 1810. Today, companies use a variety of metals,
including aluminum and steel. And they chose from many hundreds
of epoxy linings, depending on the products involved.

The main purpose of a can's lining is to protect food from both
bacteria in the environment and corrosion from compromised metal.
To do that effectively, a lining needs to stay intact while in
contact with food, a particular concern when the food is acidic.

The lining has to be flexible, to keep bending or denting of the
can from exposing its contents to contamination. And it must be
able to withstand high heat, which companies use for
sterilization after filling cans with food and sealing their
lids.

From an industry point of view, the lining should also be sturdy
and stable. The longer a company's cans remain intact, the less
money it loses in throwing spoiled products away. The invention
of BPA-based coatings, Rost said, dramatically increased the
shelf life of canned foods.

"When you pack a can with an epoxy coating, it can sit on shelves
for years at a time and be completely safe upon opening and
consuming," he said. "With older technologies, you will have cans
fail over time much, much more."

But epoxy linings raise other concerns, said toxicologist Linda
Birnbaum, director of the National Institute of Environmental
Health Sciences in Research Triangle Park, N.C.

In a recent study, Birnbaum and colleagues found traces of BPA in
a wide variety of canned foods from supermarket shelves. The
study also detected far more BPA in canned foods than in fresh or
plastic-wrapped foods.

It's not yet clear, she said, exactly what BPA's health risks
are, what levels are cause for concern, or even where most of our
exposure comes from, though it's starting to look like food is a
major source.

"There is a lot of controversy," she said. "What we're trying to
do with the research is get to the bottom of all this."

In the meantime, some alternatives are already available, and
researchers are looking for more. Eden Organics, for one, lines
its canned beans with baked-on oleoresinous c-enamel, which is
what companies used before epoxy resins were invented. According
to the company's website, Eden is the only American company to
use cans with this lining, which is a "non-toxic mixture of an
oil and a resin extracted from various plants, such as pine or
balsam fir."

But oleoresins don't work for foods like sauerkraut or tomatoes,
said Scott McCarty, director of corporate relations for the Ball
Corporation, which manufactures metal food and beverage
packaging, and makes BPA-free cans for Eden Organics. The acid in
those foods eats away at the plant-based enamel.

Oleoresins also tend to leak into food, Rost said, affecting
taste, smell and shelf life. Companies are working on a variety
of other lining options, which use materials like polyester,
acrylic, and vinyl. So far, all have drawbacks.

"Currently, there are no alternatives available to epoxy can
coatings that will work the same and be as effective for all
products packaged in cans," McCarty said. "We keep testing
different coatings, but we're not there yet."

For now, consumers have some tough choices to make. Canned fruits
and vegetables are often more affordable than fresh produce, but
BPA-based linings have unknown health consequences.

On the other hand, BPA-free cans are far more expensive than the
standard kind. Many types of canned foods aren't available in
BPA-free versions. And even if a can is labeled as BPA-free,
Birnbaum said, the food inside might still contain traces of the
chemical.

"I know one company we questioned was supposed to be BPA-free,
but our measurements of their cans showed it wasn't," she said.
She wouldn't name the company.